1. Field of the Invention
The present invention relates to the field of mobile communication technology, and more particular, to a multi-mode antenna and a base station.
2. Description of the Related Art
Currently, mobile communication networks have developed to the three generation (3G), and 3G networks have been deployed and used widely in the world. With the continuous popularization and promotion of data services and mobile internet, the International Mobile Standards Organization has developed Long Time Evolution (LTE) and 4G technical standards to meet the increasing development of network technology and service capability. Because the Multiple-Input and Multiple-Output (MIMO) technique may greatly improve the network service rate and link performance due to its sufficient use of independent spatial propagation paths, and has become one of the core techniques of LTE and future 4G technology.
For a mobile networks operator, in order to keep the continuity of old services and to provide new networks and new services, it is required to deploy and establish multiple mobile network systems at the same time. Particularly, because a LTE system adopts MIMO antennas, the network itself has a large number of antennas, along with original 2G and 3G system antennas, the number of antennas on the roof of a base station will become much higher than that of a current site location. In addition, most of current 2G and 3G networks utilize low frequency resources, for example, the 900 MHz band used by GSM, the 800 MHz band used by CDMA, and LTE and future 4G may likely use frequency bands above 2 GHz, for example, the 2 GHz or 2.6 GHz band. Because there is a huge frequency gap between the 800/900 MHz 2G systems and 2/2.6 GHz LTE systems, it is very difficult to realize a wide frequency antenna supporting several frequency bands simultaneously, and thereby it is impossible to reduce the number of antennas for future multiple system coexistence by using wide frequency antenna techniques. Further, with the increase in the number of antennas, there may be a situation of unable to add further antennas due to insufficient roof space of a site location.
Thus, how to reduce the number of physical antennas while meeting the requirement of network infrastructure establishment is a problem desired to be solved by mobile operators.